For electrically powered vehicles, such as electric vehicles or hybrid vehicles, in which an electric motor for driving the vehicle is driven by electric power from a power storage device represented by a secondary battery, a configuration of charging this power storage device from a power source external to the vehicle (hereinafter briefly referred to as “an external power source” as well) has been proposed. Hereinafter, charging of the power storage device from the external power source will be referred to as “external charging” as well.
For example, Japanese Patent Laying-Open No. 2001-163041 (Patent Document 1) discloses a configuration in which AC power obtained through a connector connectable to an external commercial power source is rectified and smoothed, and then boosted to a predetermined voltage, to thereby charge an axle driving battery. Further, Patent Document 1 discloses that a vehicle air conditioner which allows a compressor constituting a refrigerating cycle to be driven using electric charges stored in the battery is provided with a circuit that, in an ordinary state, electrically drives the compressor in the refrigerating cycle with electric power from the battery, and in the case of air-conditioning inside the vehicle being parked at a camp site or the like, disconnects the battery from a compressor driving circuit so that electric power obtained from the AC power source, then rectified and smoothed can be used directly for driving the compressor.
Accordingly, the vehicle air conditioner disclosed in Patent Document 1 can be operated for a long period of time with no concern for battery exhaustion or without continuing operating the engine during parking at a camp site or the like.
Japanese Patent Laying-Open No. 2000-299988 (Patent Document 2) discloses a commercial power source apparatus for a vehicle configured such that an outlet is automatically switchable between an inverter and a commercial power source. According to the configuration of Patent Document 2, one of AC power received from the commercial power source and AC voltage output from the inverter upon converting electric power from the battery can be selectively connected by a switch to a power outlet common to the commercial power source and the inverter.
Japanese Patent Laying-Open No. 2001-45673 (Patent Document 3) discloses a circuit configuration for an electrically driven apparatus and a battery unit thereof in which individual switches are provided in a path for charging the battery unit from a commercial power source and charging means and in an electric path from the battery unit to load driving means, respectively.    Patent Document 1: Japanese Patent Laying-Open No. 2001-163041    Patent Document 2: Japanese Patent Laying-Open No. 2000-299988    Patent Document 3: Japanese Patent Laying-Open No. 2001-45673